Principles of Genetics and Breeding

2.1.9 Dominant and recessive

• In a heterozygote only one allele of the pair is able to express itself, while the other is not able to do so. The former is known as dominant allele and the latter as recessive allele.
• The dominant allele expresses itself in the homozygous and heterozygous condition.
• A phenotypic trait or character which appears only in the homozygous individual is called a recessive trait and the pair of alleles which specifies a recessive phenotypic trait is called a recessive allele.